该数字电压表具有手动和自动测量功能，设计者完成相应的硬件和软件设计。实现技术指标包括：

　　1可测量工频交流电压

　　2电压测量精度达5/1000

　　3电压测量分5档：2.5V、10V、20V、100V、700V

　　4输入阻抗大于1MΩ。

　　5显示器可显示测量的有效值。

　　6有手动和自动按键，自动档量程自动切换

7写出程序流程图及汇编程序。-The digital voltage meter with manual and automatic measurement functions, the designer to complete the appropriate hardware and software design. Achieve technical indicators including: 1 2 measurable voltage frequency AC voltage measurement accuracy of 5/10 003 voltage measurements in 5 files: 2.5V, 10V, 20V, 100V, 700V 4 input impedance greater than 1MΩ. 5 display shows the measured RMS. 6 with manual and automatic button, automatic transmission automatic range switch 7 process flow diagram and assembler to write.